Mobile terminals have a large amount of software installed therein, and the software often needs to be upgraded so that the users can experience and use the software in a better way. Firmware Over The Air (FOTA) upgrading is a method commonly used to upgrade software in mobile terminals, and can upgrade software simply and quickly. The FOTA upgrading is mainly as follows: a difference file corresponding to differences between a file of a software package of an old version and the same file of the software package of a new version is generated according to a differential algorithm, and then the difference file is added into an FOTA upgrade package to achieve upgrading of the software.
The present inventor has found in the long-term research and development that, in the conventional method of generating an FOTA upgrade package, the difference file can only be generated for files having the same filename in the software packages of the old version and the new version; and for two files having different filenames but similar contents, a different file cannot be generated. Thus, what can be done is only to add the whole file, which has a different filename but similar contents, of the software package of the new version into the FOTA upgrade package. This makes the volume of the FOTA upgrade package larger, and increases the traffic and time taken to download the FOTA upgrade package into the mobile terminal.